"{ Package: 'stx:libbasic' }"

OSFileHandle subclass:#UnixFileDescriptorHandle
	instanceVariableNames:''
	classVariableNames:''
	poolDictionaries:''
	category:'OS-Unix'
!

!UnixFileDescriptorHandle primitiveDefinitions!
%{
#include <stdio.h>
#include <errno.h>
%}

! !


!UnixFileDescriptorHandle methodsFor:'input/output'!

readBytes:count into:aByteBuffer startingAt:firstIndex
    "read count bytes into a byte-buffer;
     Return the number of bytes read (negative on error)"

%{
    unsigned char *extPtr;
    int nRead = -1;
    INT fd = (INT)(__externalAddressVal(self));
    INT cnt, offs;
    int nInstBytes, objSize;

    if (! __bothSmallInteger(count, firstIndex)) {
        goto bad;
    }
    cnt = __smallIntegerVal(count);
    offs = __smallIntegerVal(firstIndex) - 1;

    if (fd < 0) {
        goto bad;
    }
    if (__isExternalBytesLike(aByteBuffer)) {
        OBJ sz;

        nInstBytes = 0;
        extPtr = (char *)(__externalBytesAddress(aByteBuffer));
        sz = __externalBytesSize(aByteBuffer);
        if (__isSmallInteger(sz)) {
            objSize = __smallIntegerVal(sz);
        } else {
            objSize = -1; /* unknown */
        }
    } else {
        OBJ oClass;
        int nInstVars;

        oClass = __Class(aByteBuffer);
        switch (__smallIntegerVal(__ClassInstPtr(oClass)->c_flags) & ARRAYMASK) {
            case BYTEARRAY:
            case WORDARRAY:
            case LONGARRAY:
            case SWORDARRAY:
            case SLONGARRAY:
            case FLOATARRAY:
            case DOUBLEARRAY:
                break;
            default:
                goto bad;
        }
        extPtr = (char *)0;
        nInstVars = __smallIntegerVal(__ClassInstPtr(oClass)->c_ninstvars);
        nInstBytes = __OBJS2BYTES__(nInstVars);
        objSize = __Size(aByteBuffer) - OHDR_SIZE - nInstBytes;
    }
    if ((offs >= 0)
     && (cnt >= 0)
     && ((objSize == -1) || (objSize >= (cnt + offs)))) {
        nRead = 0;

        do {
            int n;

            if (extPtr) {
                n = read(fd, extPtr+offs, cnt);
            } else {
                char *bp;

                /*
                 * on interrupt, anObject may be moved to another location.
                 * So we recompute the byte-address here.
                 */
                bp = __ByteArrayInstPtr(aByteBuffer)->ba_element + nInstBytes;

                n = read(fd, bp + offs, cnt);
            }
            if (n > 0) {
                cnt -= n;
                offs += n;
                nRead += n;
            } else {
                if (n < 0) {
                    if (errno == EINTR) {
                        continue;
                    }
                    break;
                }
            }
        } while (cnt > 0);

        RETURN (__mkSmallInteger(nRead));
    }
bad: ;   
%}.
    ^ self primitiveFailed

    "
     |h buff n|

     h := self basicNew.
     h setFileDescriptor:0.
     buff := ByteArray new:10. buff inspect.
     n := h readBytes:10 into:buff startingAt:1.
     Transcript show:n; space; showCR:buff.
    "
!

writeBytes:count from:aByteBuffer startingAt:firstIndex
    "write count bytes from a byte-buffer;
     Return the number of bytes written (negative on error)"

%{
    unsigned char *extPtr;
    int nWritten = -1;
    INT fd = (INT)(__externalAddressVal(self));
    INT cnt, offs;
    int nInstBytes, objSize;

    if (! __bothSmallInteger(count, firstIndex)) {
        goto bad;
    }
    cnt = __smallIntegerVal(count);
    offs = __smallIntegerVal(firstIndex) - 1;

    if (fd < 0) {
        goto bad;
    }
    if (__isExternalBytesLike(aByteBuffer)) {
        OBJ sz;

        nInstBytes = 0;
        extPtr = (char *)(__externalBytesAddress(aByteBuffer));
        sz = __externalBytesSize(aByteBuffer);
        if (__isSmallInteger(sz)) {
            objSize = __smallIntegerVal(sz);
        } else {
            objSize = -1; /* unknown */
        }
    } else {
        OBJ oClass;
        int nInstVars;

        oClass = __Class(aByteBuffer);
        switch (__smallIntegerVal(__ClassInstPtr(oClass)->c_flags) & ARRAYMASK) {
            case BYTEARRAY:
            case WORDARRAY:
            case LONGARRAY:
            case SWORDARRAY:
            case SLONGARRAY:
            case FLOATARRAY:
            case DOUBLEARRAY:
                break;
            default:
                goto bad;
        }
        extPtr = (char *)0;
        nInstVars = __smallIntegerVal(__ClassInstPtr(oClass)->c_ninstvars);
        nInstBytes = __OBJS2BYTES__(nInstVars);
        objSize = __Size(aByteBuffer) - OHDR_SIZE - nInstBytes;
    }
    if ((offs >= 0)
     && (cnt >= 0)
     && ((objSize == -1) || (objSize >= (cnt + offs)))) {
        nWritten = 0;

        do {
            int n;

            if (extPtr) {
                n = write(fd, extPtr+offs, cnt);
            } else {
                char *bp;

                /*
                 * on interrupt, anObject may be moved to another location.
                 * So we recompute the byte-address here.
                 */
                bp = __ByteArrayInstPtr(aByteBuffer)->ba_element + nInstBytes;

                n = write(fd, bp + offs, cnt);
            }
            if (n > 0) {
                cnt -= n;
                offs += n;
                nWritten += n;
            } else {
                if (n < 0) {
                    if (errno == EINTR) {
                        continue;
                    }
                    break;
                }
            }
        } while (cnt > 0);

        RETURN (__mkSmallInteger(nWritten));
    }
bad: ;   
%}.
    ^ self primitiveFailed

    "
     |h buff n|

     h := self basicNew.
     h setFileDescriptor:1.
     buff := '12345678901234567890'.
     n := h writeBytes:10 from:buff startingAt:1.
    "
! !

!UnixFileDescriptorHandle methodsFor:'private accessing'!

setFileDescriptor:anInteger

%{
    if (__isSmallInteger(anInteger)) {
        __externalAddressVal(self) = (OBJ)(__smallIntegerVal(anInteger));
    }
%}


! !

!UnixFileDescriptorHandle methodsFor:'release'!

closeFile
    "close the underlying file"

%{
    INT fd = (INT)(__externalAddressVal(self));

    if (fd > 0) {
        __externalAddressVal(self) = (OBJ)-1;
        close(fd);
    }
%}.

! !

!UnixFileDescriptorHandle class methodsFor:'documentation'!

version
    ^ '$Header: /cvs/stx/stx/libbasic/UnixFileDescriptorHandle.st,v 1.6 2003-04-10 23:36:50 cg Exp $'
! !